Steam turbine



Jan. 24, 1928. 1,657,233

T. STEIN STEAM TURBINE Filed May 27. 1926 Accumu lafor Inventov: Theodow- Stein,

by His Attorney.

Patented Jan. 24, 1928.

UNITED STATES THEODOB STEIN, 0F FRIEDENAU, GERMANY, ASSIGNOR TO GENERAL ELECTRIC PAN Y, A CORPORATION OF NEW YORK.

PATENT A orr cs.

com-

STEAM TURBINE.

Application filed May 27, 1926, Serial No. 112,132, and in Germany June 19, 1925.

. cially to mixed pressure turbine installations wherein the low pressure steam is supplied from a steam accumulator. As is known,

a steam accumulator is a steam. storage reservoir which is adapted to receive low pres sure steam intermittently from one or more sources of supply and deliver a steady supply of steam to the turbine.

The object of my invention is to provide an improved regulating means for a mixed pressure turbine and is particularly well adapted for use in cases wherein the supply of low pressure steam is obtained from a steam accumulator, and for a consideration of what I believe. to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, the figure is a diagrammatic view of a turbine regulating means embodying my invention, the parts being shown in positions they occupy under certain operating conditions.

Referring to the drawing, 1 indicates a base plate upon which is mounted a turbine comprising a high pressure section 2 and a low ressure section 3, the two sections being own in the present instance, as being located in separate turbine shells. High pressure steam is supplied to turbine 2 by a conduit 4 and the exhaust from turbine 2 is conveyed to the high pressure end of turbine 3 by a conduit 5. Theexhaust from turbine section 3 is conveyed by an exhaust conduit 6 to a suitable condenser 7. 8 is a steam accumulator adapted to receive steam from a suitablesource of supply through a.

conduit 9 and to deliver steam through a conduit 10 to the high pressure end of turbine section 3. The turbine construction so far described is to be taken as typical of any suitable mixed pressure turbine receiving steam from a high pressure source and also from an accumulator.

In conduit 4 is a suitable valve means 11 which controls the supply of high pressure steam to turbine section 2. It has a stem 12 which is pivotally connectedat 13 to one end of a lever 14. The other end of lever 14 is pivoted at 15 to a stem 16. the lower end of which is connected to a valve means 17 which controls the flow of steam from accumulator 8 to low pressure turbine section 3. The upper end of stem 16 is pro vided with a flat head 18 which forms an abutment adapted to engage a head or abutment 19 on the lower end of a rod 20. Connected to lever 14 is a suitable speed governor 21 operated in a suitable manner from the shaft of the turbine. The upper end of stem 12 is connected by a spring 22 to a fixed wall 23. The upper end of rod 20 is pivotally connected to the central portion of a floating lever 24. One end of lever 24 carries a head 25 which has threaded engagement with a rod 26 provided with a hand-wheel 27. By turning hand-wheel 27 in'one direction or the other, the left-hand end of lever 24 can be raised or lowered. The other end of lever 24 is pivotally connected at 28 to stem 29. The upper end of stem 29 is connected to a piston 30 which moves in a cylinder 31. In cylinder 31 above-piston 30 is a spring 32 which acts 1n a dlI'GCtlOIl tending to-move piston 30 downward. The lower end of stem 29 is provided with a head 33 adapted to engage a plate 34 beneath which is located a spring 35. 36 is a stop which serves to limit the upward movement of plate 34. Cylinder 31 beneath piston 30 is connected by a pipe 37 to conduit 10 so that piston 30 is subjected to the pressure of the steam supplied through conduit 10 to the turbine. a

Spring 32's stronger than spring 35 and is capab e of moving piston 30 downward against the action of spring 35 when the pressure under piston 30 decreases below a certain predetermined low value. On the other hand, the pressure 'underpiston 30 is capable of moving piston 30 upward against the action of spring 32 when the pressure exceeds a predetermined high value. For all pressures between these two limits, piston 30 remains stationary by reason of the fact that within such limits spring 32 is not strong enou h to move plston 30 downward against t e pressure on the underside of piston 30 and the pressure of spring 35, while on the other hand, the pressure under piston 30 is not suflicient alone to move piston 30 upward against the action of spring 32, and further assistance of spring 35 is not available because plate 34 is now in contact with stops 36. In this connection it will be understood that spring 35 is under a certain amount of compression but by reason of the fact that plate 34 is in contaot'with stops 36, itwill not assist in a result, the amount which valve means 17 is opened comes entirely under the control of the'manual, adjusting means comprising the handwheel 27. This is due to the fact that valve means 17 can be opened only until head 18 on the upper end of the stem 16 engages the head 19 on the lower end of rod 20. Hand-wheel 27 is adjusted to bring head 19- to a position such that valve means 17 may be opened to an extent suflicient to take the mean supply of steam from accumulator 8. In this connection it will be understood that the amount of low pressure steam supplied to an accumulator from intermittent sources may vary considerably from time to time and it is desirable that valve means 17 be set for the mean supply. The accumulator then takes care of the fluctuations in steam supply, storing steam when it receives a supply in excess of that furnished to the turbine and giving up steam when the supply received is less than that furnished to the turbine.

' When the turbine is operating at no load or substantially noload,the speed governor willv hold valve 11 closed and valve ,17 substantiall closed, admitting only enough elastic uidfrom accumulator 8 to run the turbine atvitsno load or substantially no load speed. Now, as the speed decreases due to increase of load, for -example,speed governor 21 serves first to open valve means 17 until head 18 engages'head 19 after which it opens valve means 11 against'the action of spring 22, spring 22 being placed under compression. Now as the speed of the turbine varies, valve means 11 will be opened and closed to regulate the turbine, lever 14 turning on pivot as a fulcrum. During this operation, when the speed of the turbine decreases, valve means :11 is moved upward opening further the valve means and compressin further the spring 22, while when the spec increases spring 22 effects 'a movement of valve means 11 toward closed position. Thus it will be seen that the speed governor acts only on the high pressure holds valves 17 and 11 in open position, the opening of valve 17 being limited, of course, by the position of stop 19.

If the pressure in the accumulator increases above the predetermined high value, piston will be moved upward to effect a further opening of valve means 17 other hand, if the pressure in accumulator 8 falls below the predetermined low value,

then spring 32 will move piston 30 downward against the action of spring 35 to close somewhat valve means, 17. Thus it will be seen that while valve means 17 ordi narily is stationary and under manual control only, nevertheless its position is changed in case the steam pressure exceeds a prede' termined high value or falls below a predetermined low value. This is animportant feature of my invention because by such arrangement there is provided a certain pres sure range within whichthe accumulator may operate. It will be understood in ,CODDQC. tion with the operation of an accumulator" that its operation in supplying additional steam or in storing steam depends upon change in pressure in the accumulator, the steam being stored in the form of hot water which gives off steam when the pressure decreases and serves to condense steam and store it when the pressure increases. There fore, it is required that certain pressure changes occur in order for the accumulator to function advantageously. The pressure change which may occur depends upon the regulator comprising piston 30 and may be given a suitable value by adjusting springs 32 and 35.

In accordance, with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention maybe carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United Statesis:

1. The combination with a mixedpres sure turbine having a conduit for supplying high pressure elastic fluid to it, aconduit for supplying low pressure elastic fluid to it, valve means in each ofsa-id' conduits, and governor means for actuating said valve means, of manually-operated means for a limiting the extent to which the low pressure valve means may be opened by said governor means, and means for efi'ectinga closing movement of said low pressure valve On the means when the pressure of the low pressure elastic fluid decreases below a predetermined low value.

2. The combination with a mixedpressure turbine having a conduit for supplying high pressure elastic fluid to it, a conduit for supplying low pressure elastic fluid to it, valve means in each of said conduits, and a governor means for actuating said valve means, of manually-operated means for limiting the extent to which the low pres sure valve means may be opened by said governor means, means for effecting a closing movement of said low pressure valve means when the pressure of the low pressure elastic fluid decreases below a predetermined low value, and means for efiecting an open ing movement of said low pressure valve means when the pressure of the low pressure elastic fluid increases above a predetermined high value.

3. The combination with a mixed pressure turbine having a conduit for supplying high pressure elastic fluid to it, a conduit for supplying low pressure elastic fluid to' it, and valve means in each of said conduits, of a speed governor for effecting the opening of both said valve means, a stop for limiting the opening movement of the low pressure valve means, manually operated means for posi tioning said stop, and means for moving said stop independently of said manuallyoperated means when the pressure of the low pressure elastic fluid decrease below a predetermined low value.

4. The combination with a mixed pressure turbine having a conduit for supplying high pressure elastic fluid to it, a conduit for supplying low pressure elastic fluid to it,

and valve means in each of said conduits, of a speed governor for effecting the opening of both said valve means, a stop for limiting the opening movement of the low pressure valve means, manually-operated means for positioning said stop, means for moving said stop independently of said manuallyoperated means when the pressure of the low pressure elastic fluid decreases below a predetermined low value, and means whereby an opening movement of said low pressure valve means may be effected when the pressure of the low pressure elastic fluid increases above a predetermined high value.

5. The combination with a mixed pressure turbine having a conduit for supplying high pressure elastic fluid to it, a conduit for supplying low pressure elastic fluid to it, and valve means in each of said conduits, of a speed governor for effecting the opening of both said valve means, a stop for limiting the opening movement of the low pressure valve means, a floating lever to which the stop is connected, manuallypperable means for positioning one end of said floating lever, a pressureresponsive device which is moved by certain predetermined high and low pressure values, and aconduit connect ing said pressure responsive device to the low pressure supply conduit.

In witness whereof I have hereunto set my hand this 6th day of May, 1926.

THEODOR STEIN. 

